You can add booleans by typing two & signs between them. _1&&_2If you want to store the result in a variable, you type: _result = _1&&_2If you want that the _result variable changes when the value of _1 or _2 changes, you type: _result = {_1&&_2}

Oh, I misunderstood your question. You can add thing to the script box by typing the thing you want to add in the black square at the top.Type _aaa = 15 in the black square and a variable will appear named _aaa with value 15.You can use that variable in another script, like when you spawn a circle you can write density := 10; but you could also write density = _aaa; in that case the density will be the value stored in the variable _aaa.